ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 8, pp. 1465–1468. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © I.A. Novakov, S.S. Radchenko, F.S. Radchenko, A.S. Ozerin, A.V. Karaulov, 2008, published in Zhurnal Prikladnoi Khimii, 2008,
Vol. 81, No. 8, pp. 1389–1393.
Formulations as Waterproofing Agents for Oil Pool
I. A. Novakov, S. S. Radchenko, F. S. Radchenko, A. S. Ozerin, and A. V. Karaulov
Volgograd State Technical University, Volgograd, Russia
Lukoil-Volgograd NIPImorneft’ Limited Liability Company, Volgograd, Russia
Received November 1, 2007
Abstract—Gel-forming polyacrylamide (PAA)–aluminum pentahydroxochloride (APHC) formulaitons were
studied as waterproofing agents for an oil pool. The optimal formula and the gelation rate were determined.
AND POLYMERIC MATERIALS
The majority of methods for raising the oil recov-
ery from oil strata are based on flooding. Breakthrough
of injected and stratal waters through areas with high
filtration properties results in the formation of flooded-
out regions. Water is filtered through these regions,
bypassing low-permeable oil-bearing areas of a pay.
The oil production decreases and water content of oil
To raise the oil recovery from oil pools, chemi-
cals that form a waterproofing shield in highly watered
interlayer, which prevents water penetration in produc-
ing oil wells, are pumped in .
However, most of these chemicals have signifi-
cant disadvantages. Among them is the high cost, con-
tamination of underground and surface waters, poor
technological properties, and short life of the protect-
ing shields. To selectively protect strata from water,
gel-forming formulations of organic, inorganic, or or-
ganomineral compounds are used and, in particular,
a mixture of a polyacrylamide (PAA) solution, alumi-
num salt, and urea (U) [2, 3]. The resulting aluminum
hydroxide gel is a polydisperse system with poor and
nonuniform adhesion to the stratum rock. Although an in-
troduction of polyacrylamide improves the adhesion,
the resulting system is freely disperse and is gradually
washed out from the collector by injected or stratal
A gel-forming formulation containing aluminum
pentahydroxochloride (APHC) yields a more stable and
longer-lived gel. Colloidal polymer complex (CPC) 
is almost instantaneously formed by the reaction of
APHC with polyacrylamide in the starting solution.
Urea introduced in the course of preparation of the start-
ing solution decomposes in a stratum. The hydrolysis
product initiates hydrolysis of the aluminum salt . As
a result, a stable strong gel-in-gel (combined gel) dis-
persion resistant to washout is formed.
The aim of this study was to develop a gel-forming
PAA-APHC formulation for water-shutoff of oil pools,
to find the best formula, to determine the gelation rate,
and to estimate waterproof properties of this gel to-
ward oil pools.
Aluminum pentahydroxochloride prepared by the pat-
ented procedure  had the following properties: Al
content 12.8 wt
atomic ratio 0.48, pH 4.5,
ρ = 1330 kg
, dry residue 46.5 wt
%. PAA with mo-
lecular weight of 6 × 10
was purchased from ACROS
Company (USA), and urea, from Ekros Company
(Russia). The formulations were prepared by mixing
an aqueous PAA solution (1 wt
%) with an aqueous
APHC solution and urea at room temperature.
The instant of gelation was visually determined
by the absence of fluidity of the liquid and more pre-
cisely by the solution viscosity measured with a Reoki-
netika-M vibration viscometer with a temperature-
controlled cell. The vibration frequency was 750 Hz,
and amplitude, 0.02 mm.